What are crippling walls?

Some structures are built on cripple walls. As shown in the figure, a cripple wall is a short wall that rests on the foundation and supports the floor and exterior walls. If the cripple wall is not braced, it can shift during an earthquake.

Why do they call it a cripple wall?

It's called a cripple wall because that section of the home is considered a “cripple zone” - in seismic events it was thought that homes should have an area that cripples/gives out so that the rest of the home would go undamaged.

How does a cripple wall work?

Wooden floors and stud walls are sometimes built on top of an exterior foundation to support a house and create a crawl space. These are called cripple walls and they carry the weight of the house. During an earthquake, these walls can collapse if they are not braced to resist horizontal movement.

What is a cripple in construction?

In carpentry, the term “cripple” refers to a special-purpose wall stud or roof rafter. A cripple stud is located above a door or window or below a window. A cripple rafter runs from hip to valley on a roof or is cut short to allow for an opening such as a chimney or skylight.

How do you fix a crippled wall?

Cripple walls are braced by nailing plywood sheathing to the inside of the walls that surround the crawlspace. A licensed contractor can complete a retrofit for houses with cripple walls shorter than four feet, or a skilled homeowner can do it, following a standard plan set.

What is a cripple wall and how are they vulnerable in earthquakes? Home Earthquake Vulnerabilities

Are cripple walls still used?

Cripple walls are typically found on dwellings built prior to 1960. Many newer dwellings utilize concrete perimeter walls to elevate or level the dwelling. These are not cripple walls.

What is a shear wall in a building?

shear wall, In building construction, a rigid vertical diaphragm capable of transferring lateral forces from exterior walls, floors, and roofs to the ground foundation in a direction parallel to their planes. Examples are the reinforced-concrete wall or vertical truss.

Are cripple studs necessary?

Cripple Studs – short studs installed above a header or below a window sill or saddle. If the header is tall enough to reach the top plate no cripple studs are required.

What is a pony wall in a house?

A pony wall is nothing more than a short wall, and the term is often used interchangeably with “knee wall” or “cripple wall.” Pony walls, like regular walls, have top and bottom plates, that is, the horizontal members that the vertical studs fasten to.

What is the bottom stud in a wall called?

The studs are the vertical pieces that make up most of a wall's frame. The cavities between the studs are called bays (or stud bays). A horizontal piece at the bottom of the wall is called the bottom plate. The studs are nailed to this plate, which is nailed to the floor.

How do you tell if your house is bolted to the foundation?

How much does it cost to earthquake proof your house?

While there is not a standard cost for strengthening your home against earthquake damage, the range usually is about $3,000 to $7,000. Larger homes, those built on hillsides and those with basements and rooms over garages will typically cost more to retrofit.

Is the dwelling elevated on cripple stud walls?

Cripple walls are used to support a dwelling between the concrete foundation and the floor of a dwelling and to elevate the dwelling above ground to allow access to the utility lines or to level a dwelling built on a slope. Crawl space is the area created underneath the floor.

What is retrofitting a foundation?

Earthquake retrofitting (seismically retrofitting) a house is done to prevent displacement from the structure's concrete foundation. This makes a building safer and less likely to suffer damage during an earthquake. Retrofitting single-family homes is considered one of the cheapest seismic improvements available.

What is wall Bracing and its purpose?

Wall bracing is used to protect life by minimizing structural damage to a building in freak storms and earthquakes. All buildings are required to have some form of lateral bracing. Exterior and interior wall coverings are usually used with conventional light-frame construction.

What is the maximum spacing for 2x4 studs?

In walls supporting only a roof and ceiling, 2x4 studs can be spaced up to 24 inches on-center, except for Utility grade (No. 3) studs.

What are dwarf walls?

Definition of dwarf wall

: a low toe wall built to retain the slope of an excavation or embankment.

Why is it called a knee wall?

The term is derived from the association with a human knee, partly bent. Knee walls are common in houses in which the ceiling on the top floor is an attic, i.e. the ceiling is the underside of the roof and slopes down on one or more sides.

What is a stub wall?

A low wall, monolithically placed with a concrete floor (or other members) so as to provide for the control and attachment of wall forms.

Does a double top plate mean load bearing?

I know a double top plate usually means it's load bearing, but parallel with trusses means it's usually not load bearing.

Do all houses have shear walls?

Almost all houses have external shear walls, but internal shear walls are typically found only in larger houses and high-rise buildings subject to lateral winds and seismic forces. The taller the building, the greater the need for internal shear walls and a lateral force resisting system.

Why do buildings need shear walls?

Tall multi-story buildings require shear core walls to resist damaging lateral forces from strong winds and earthquakes. Shear core construction occurs in the building's center, typically encased in box-shaped sections around an elevator or a stairway.